From e0f3c39b7587dd0b7d90d62dd40b42a0d76a27b5 Mon Sep 17 00:00:00 2001
From: syuilo <4439005+syuilo@users.noreply.github.com>
Date: Fri, 23 Aug 2024 12:30:05 +0900
Subject: [PATCH] Create EmPagination.vue

---
 .../embed/src/components/EmPagination.vue     | 508 ++++++++++++++++++
 1 file changed, 508 insertions(+)
 create mode 100644 packages/embed/src/components/EmPagination.vue

diff --git a/packages/embed/src/components/EmPagination.vue b/packages/embed/src/components/EmPagination.vue
new file mode 100644
index 0000000000..4696dc377e
--- /dev/null
+++ b/packages/embed/src/components/EmPagination.vue
@@ -0,0 +1,508 @@
+<!--
+SPDX-FileCopyrightText: syuilo and misskey-project
+SPDX-License-Identifier: AGPL-3.0-only
+-->
+
+<template>
+<Transition
+	:enterActiveClass="$style.transition_fade_enterActive"
+	:leaveActiveClass="$style.transition_fade_leaveActive"
+	:enterFromClass="$style.transition_fade_enterFrom"
+	:leaveToClass="$style.transition_fade_leaveTo"
+	mode="out-in"
+>
+	<MkLoading v-if="fetching"/>
+
+	<MkError v-else-if="error" @retry="init()"/>
+
+	<div v-else-if="empty" key="_empty_" class="empty">
+		<slot name="empty">
+			<div class="_fullinfo">
+				<img :src="infoImageUrl" class="_ghost"/>
+				<div>{{ i18n.ts.nothing }}</div>
+			</div>
+		</slot>
+	</div>
+
+	<div v-else ref="rootEl">
+		<div v-show="pagination.reversed && more" key="_more_" class="_margin">
+			<MkButton v-if="!moreFetching" v-appear="(enableInfiniteScroll && !props.disableAutoLoad) ? appearFetchMoreAhead : null" :class="$style.more" :disabled="moreFetching" :style="{ cursor: moreFetching ? 'wait' : 'pointer' }" primary rounded @click="fetchMoreAhead">
+				{{ i18n.ts.loadMore }}
+			</MkButton>
+			<MkLoading v-else class="loading"/>
+		</div>
+		<slot :items="Array.from(items.values())" :fetching="fetching || moreFetching"></slot>
+		<div v-show="!pagination.reversed && more" key="_more_" class="_margin">
+			<MkButton v-if="!moreFetching" v-appear="(enableInfiniteScroll && !props.disableAutoLoad) ? appearFetchMore : null" :class="$style.more" :disabled="moreFetching" :style="{ cursor: moreFetching ? 'wait' : 'pointer' }" primary rounded @click="fetchMore">
+				{{ i18n.ts.loadMore }}
+			</MkButton>
+			<MkLoading v-else class="loading"/>
+		</div>
+	</div>
+</Transition>
+</template>
+
+<script lang="ts">
+import { computed, ComputedRef, isRef, nextTick, onActivated, onBeforeMount, onBeforeUnmount, onDeactivated, ref, shallowRef, watch } from 'vue';
+import * as Misskey from 'misskey-js';
+import { misskeyApi } from '@/scripts/misskey-api.js';
+import { onScrollTop, isTopVisible, getBodyScrollHeight, getScrollContainer, onScrollBottom, scrollToBottom, scroll, isBottomVisible } from '@/scripts/scroll.js';
+import { useDocumentVisibility } from '@/scripts/use-document-visibility.js';
+import { i18n } from '@/i18n.js';
+
+const SECOND_FETCH_LIMIT = 30;
+const TOLERANCE = 16;
+const APPEAR_MINIMUM_INTERVAL = 600;
+
+export type Paging<E extends keyof Misskey.Endpoints = keyof Misskey.Endpoints> = {
+	endpoint: E;
+	limit: number;
+	params?: Misskey.Endpoints[E]['req'] | ComputedRef<Misskey.Endpoints[E]['req']>;
+
+	/**
+	 * 検索APIのような、ページング不可なエンドポイントを利用する場合
+	 * (そのようなAPIをこの関数で使うのは若干矛盾してるけど)
+	 */
+	noPaging?: boolean;
+
+	/**
+	 * items 配列の中身を逆順にする(新しい方が最後)
+	 */
+	reversed?: boolean;
+
+	offsetMode?: boolean;
+
+	pageEl?: HTMLElement;
+};
+
+type MisskeyEntityMap = Map<string, MisskeyEntity>;
+
+function arrayToEntries(entities: MisskeyEntity[]): [string, MisskeyEntity][] {
+	return entities.map(en => [en.id, en]);
+}
+
+function concatMapWithArray(map: MisskeyEntityMap, entities: MisskeyEntity[]): MisskeyEntityMap {
+	return new Map([...map, ...arrayToEntries(entities)]);
+}
+
+</script>
+<script lang="ts" setup>
+import { infoImageUrl } from '@/instance.js';
+import MkButton from '@/components/MkButton.vue';
+
+const props = withDefaults(defineProps<{
+	pagination: Paging;
+	disableAutoLoad?: boolean;
+	displayLimit?: number;
+}>(), {
+	displayLimit: 20,
+});
+
+const emit = defineEmits<{
+	(ev: 'queue', count: number): void;
+	(ev: 'status', error: boolean): void;
+}>();
+
+const rootEl = shallowRef<HTMLElement>();
+
+// 遡り中かどうか
+const backed = ref(false);
+
+const scrollRemove = ref<(() => void) | null>(null);
+
+/**
+ * 表示するアイテムのソース
+ * 最新が0番目
+ */
+const items = ref<MisskeyEntityMap>(new Map());
+
+/**
+ * タブが非アクティブなどの場合に更新を貯めておく
+ * 最新が0番目
+ */
+const queue = ref<MisskeyEntityMap>(new Map());
+
+const offset = ref(0);
+
+/**
+ * 初期化中かどうか（trueならMkLoadingで全て隠す）
+ */
+const fetching = ref(true);
+
+const moreFetching = ref(false);
+const more = ref(false);
+const preventAppearFetchMore = ref(false);
+const preventAppearFetchMoreTimer = ref<number | null>(null);
+const isBackTop = ref(false);
+const empty = computed(() => items.value.size === 0);
+const error = ref(false);
+const {
+	enableInfiniteScroll,
+} = defaultStore.reactiveState;
+
+const contentEl = computed(() => props.pagination.pageEl ?? rootEl.value);
+const scrollableElement = computed(() => contentEl.value ? getScrollContainer(contentEl.value) : document.body);
+
+const visibility = useDocumentVisibility();
+
+let isPausingUpdate = false;
+let timerForSetPause: number | null = null;
+const BACKGROUND_PAUSE_WAIT_SEC = 10;
+
+// 先頭が表示されているかどうかを検出
+// https://qiita.com/mkataigi/items/0154aefd2223ce23398e
+const scrollObserver = ref<IntersectionObserver>();
+
+watch([() => props.pagination.reversed, scrollableElement], () => {
+	if (scrollObserver.value) scrollObserver.value.disconnect();
+
+	scrollObserver.value = new IntersectionObserver(entries => {
+		backed.value = entries[0].isIntersecting;
+	}, {
+		root: scrollableElement.value,
+		rootMargin: props.pagination.reversed ? '-100% 0px 100% 0px' : '100% 0px -100% 0px',
+		threshold: 0.01,
+	});
+}, { immediate: true });
+
+watch(rootEl, () => {
+	scrollObserver.value?.disconnect();
+	nextTick(() => {
+		if (rootEl.value) scrollObserver.value?.observe(rootEl.value);
+	});
+});
+
+watch([backed, contentEl], () => {
+	if (!backed.value) {
+		if (!contentEl.value) return;
+
+		scrollRemove.value = (props.pagination.reversed ? onScrollBottom : onScrollTop)(contentEl.value, executeQueue, TOLERANCE);
+	} else {
+		if (scrollRemove.value) scrollRemove.value();
+		scrollRemove.value = null;
+	}
+});
+
+// パラメータに何らかの変更があった際、再読込したい（チャンネル等のIDが変わったなど）
+watch(() => [props.pagination.endpoint, props.pagination.params], init, { deep: true });
+
+watch(queue, (a, b) => {
+	if (a.size === 0 && b.size === 0) return;
+	emit('queue', queue.value.size);
+}, { deep: true });
+
+watch(error, (n, o) => {
+	if (n === o) return;
+	emit('status', n);
+});
+
+async function init(): Promise<void> {
+	items.value = new Map();
+	queue.value = new Map();
+	fetching.value = true;
+	const params = props.pagination.params ? isRef(props.pagination.params) ? props.pagination.params.value : props.pagination.params : {};
+	await misskeyApi<MisskeyEntity[]>(props.pagination.endpoint, {
+		...params,
+		limit: props.pagination.limit ?? 10,
+		allowPartial: true,
+	}).then(res => {
+		for (let i = 0; i < res.length; i++) {
+			const item = res[i];
+			if (i === 3) item._shouldInsertAd_ = true;
+		}
+
+		if (res.length === 0 || props.pagination.noPaging) {
+			concatItems(res);
+			more.value = false;
+		} else {
+			if (props.pagination.reversed) moreFetching.value = true;
+			concatItems(res);
+			more.value = true;
+		}
+
+		offset.value = res.length;
+		error.value = false;
+		fetching.value = false;
+	}, err => {
+		error.value = true;
+		fetching.value = false;
+	});
+}
+
+const reload = (): Promise<void> => {
+	return init();
+};
+
+const fetchMore = async (): Promise<void> => {
+	if (!more.value || fetching.value || moreFetching.value || items.value.size === 0) return;
+	moreFetching.value = true;
+	const params = props.pagination.params ? isRef(props.pagination.params) ? props.pagination.params.value : props.pagination.params : {};
+	await misskeyApi<MisskeyEntity[]>(props.pagination.endpoint, {
+		...params,
+		limit: SECOND_FETCH_LIMIT,
+		...(props.pagination.offsetMode ? {
+			offset: offset.value,
+		} : {
+			untilId: Array.from(items.value.keys()).at(-1),
+		}),
+	}).then(res => {
+		for (let i = 0; i < res.length; i++) {
+			const item = res[i];
+			if (i === 10) item._shouldInsertAd_ = true;
+		}
+
+		const reverseConcat = _res => {
+			const oldHeight = scrollableElement.value ? scrollableElement.value.scrollHeight : getBodyScrollHeight();
+			const oldScroll = scrollableElement.value ? scrollableElement.value.scrollTop : window.scrollY;
+
+			items.value = concatMapWithArray(items.value, _res);
+
+			return nextTick(() => {
+				if (scrollableElement.value) {
+					scroll(scrollableElement.value, { top: oldScroll + (scrollableElement.value.scrollHeight - oldHeight), behavior: 'instant' });
+				} else {
+					window.scroll({ top: oldScroll + (getBodyScrollHeight() - oldHeight), behavior: 'instant' });
+				}
+
+				return nextTick();
+			});
+		};
+
+		if (res.length === 0) {
+			if (props.pagination.reversed) {
+				reverseConcat(res).then(() => {
+					more.value = false;
+					moreFetching.value = false;
+				});
+			} else {
+				items.value = concatMapWithArray(items.value, res);
+				more.value = false;
+				moreFetching.value = false;
+			}
+		} else {
+			if (props.pagination.reversed) {
+				reverseConcat(res).then(() => {
+					more.value = true;
+					moreFetching.value = false;
+				});
+			} else {
+				items.value = concatMapWithArray(items.value, res);
+				more.value = true;
+				moreFetching.value = false;
+			}
+		}
+		offset.value += res.length;
+	}, err => {
+		moreFetching.value = false;
+	});
+};
+
+const fetchMoreAhead = async (): Promise<void> => {
+	if (!more.value || fetching.value || moreFetching.value || items.value.size === 0) return;
+	moreFetching.value = true;
+	const params = props.pagination.params ? isRef(props.pagination.params) ? props.pagination.params.value : props.pagination.params : {};
+	await misskeyApi<MisskeyEntity[]>(props.pagination.endpoint, {
+		...params,
+		limit: SECOND_FETCH_LIMIT,
+		...(props.pagination.offsetMode ? {
+			offset: offset.value,
+		} : {
+			sinceId: Array.from(items.value.keys()).at(-1),
+		}),
+	}).then(res => {
+		if (res.length === 0) {
+			items.value = concatMapWithArray(items.value, res);
+			more.value = false;
+		} else {
+			items.value = concatMapWithArray(items.value, res);
+			more.value = true;
+		}
+		offset.value += res.length;
+		moreFetching.value = false;
+	}, err => {
+		moreFetching.value = false;
+	});
+};
+
+/**
+ * Appear（IntersectionObserver）によってfetchMoreが呼ばれる場合、
+ * APPEAR_MINIMUM_INTERVALミリ秒以内に2回fetchMoreが呼ばれるのを防ぐ
+ */
+const fetchMoreApperTimeoutFn = (): void => {
+	preventAppearFetchMore.value = false;
+	preventAppearFetchMoreTimer.value = null;
+};
+const fetchMoreAppearTimeout = (): void => {
+	preventAppearFetchMore.value = true;
+	preventAppearFetchMoreTimer.value = window.setTimeout(fetchMoreApperTimeoutFn, APPEAR_MINIMUM_INTERVAL);
+};
+
+const appearFetchMore = async (): Promise<void> => {
+	if (preventAppearFetchMore.value) return;
+	await fetchMore();
+	fetchMoreAppearTimeout();
+};
+
+const appearFetchMoreAhead = async (): Promise<void> => {
+	if (preventAppearFetchMore.value) return;
+	await fetchMoreAhead();
+	fetchMoreAppearTimeout();
+};
+
+const isTop = (): boolean => isBackTop.value || (props.pagination.reversed ? isBottomVisible : isTopVisible)(contentEl.value!, TOLERANCE);
+
+watch(visibility, () => {
+	if (visibility.value === 'hidden') {
+		timerForSetPause = window.setTimeout(() => {
+			isPausingUpdate = true;
+			timerForSetPause = null;
+		},
+		BACKGROUND_PAUSE_WAIT_SEC * 1000);
+	} else { // 'visible'
+		if (timerForSetPause) {
+			clearTimeout(timerForSetPause);
+			timerForSetPause = null;
+		} else {
+			isPausingUpdate = false;
+			if (isTop()) {
+				executeQueue();
+			}
+		}
+	}
+});
+
+/**
+ * 最新のものとして1つだけアイテムを追加する
+ * ストリーミングから降ってきたアイテムはこれで追加する
+ * @param item アイテム
+ */
+const prepend = (item: MisskeyEntity): void => {
+	if (items.value.size === 0) {
+		items.value.set(item.id, item);
+		fetching.value = false;
+		return;
+	}
+
+	if (isTop() && !isPausingUpdate) unshiftItems([item]);
+	else prependQueue(item);
+};
+
+/**
+ * 新着アイテムをitemsの先頭に追加し、displayLimitを適用する
+ * @param newItems 新しいアイテムの配列
+ */
+function unshiftItems(newItems: MisskeyEntity[]) {
+	const length = newItems.length + items.value.size;
+	items.value = new Map([...arrayToEntries(newItems), ...items.value].slice(0, props.displayLimit));
+
+	if (length >= props.displayLimit) more.value = true;
+}
+
+/**
+ * 古いアイテムをitemsの末尾に追加し、displayLimitを適用する
+ * @param oldItems 古いアイテムの配列
+ */
+function concatItems(oldItems: MisskeyEntity[]) {
+	const length = oldItems.length + items.value.size;
+	items.value = new Map([...items.value, ...arrayToEntries(oldItems)].slice(0, props.displayLimit));
+
+	if (length >= props.displayLimit) more.value = true;
+}
+
+function executeQueue() {
+	unshiftItems(Array.from(queue.value.values()));
+	queue.value = new Map();
+}
+
+function prependQueue(newItem: MisskeyEntity) {
+	queue.value = new Map([[newItem.id, newItem], ...queue.value].slice(0, props.displayLimit) as [string, MisskeyEntity][]);
+}
+
+/*
+ * アイテムを末尾に追加する（使うの？）
+ */
+const appendItem = (item: MisskeyEntity): void => {
+	items.value.set(item.id, item);
+};
+
+const removeItem = (id: string) => {
+	items.value.delete(id);
+	queue.value.delete(id);
+};
+
+const updateItem = (id: MisskeyEntity['id'], replacer: (old: MisskeyEntity) => MisskeyEntity): void => {
+	const item = items.value.get(id);
+	if (item) items.value.set(id, replacer(item));
+
+	const queueItem = queue.value.get(id);
+	if (queueItem) queue.value.set(id, replacer(queueItem));
+};
+
+onActivated(() => {
+	isBackTop.value = false;
+});
+
+onDeactivated(() => {
+	isBackTop.value = props.pagination.reversed ? window.scrollY >= (rootEl.value ? rootEl.value.scrollHeight - window.innerHeight : 0) : window.scrollY === 0;
+});
+
+function toBottom() {
+	scrollToBottom(contentEl.value!);
+}
+
+onBeforeMount(() => {
+	init().then(() => {
+		if (props.pagination.reversed) {
+			nextTick(() => {
+				setTimeout(toBottom, 800);
+
+				// scrollToBottomでmoreFetchingボタンが画面外まで出るまで
+				// more = trueを遅らせる
+				setTimeout(() => {
+					moreFetching.value = false;
+				}, 2000);
+			});
+		}
+	});
+});
+
+onBeforeUnmount(() => {
+	if (timerForSetPause) {
+		clearTimeout(timerForSetPause);
+		timerForSetPause = null;
+	}
+	if (preventAppearFetchMoreTimer.value) {
+		clearTimeout(preventAppearFetchMoreTimer.value);
+		preventAppearFetchMoreTimer.value = null;
+	}
+	scrollObserver.value?.disconnect();
+});
+
+defineExpose({
+	items,
+	queue,
+	backed: backed.value,
+	more,
+	reload,
+	prepend,
+	append: appendItem,
+	removeItem,
+	updateItem,
+});
+</script>
+
+<style lang="scss" module>
+.transition_fade_enterActive,
+.transition_fade_leaveActive {
+	transition: opacity 0.125s ease;
+}
+.transition_fade_enterFrom,
+.transition_fade_leaveTo {
+	opacity: 0;
+}
+
+.more {
+	margin-left: auto;
+	margin-right: auto;
+}
+</style>